OpenSlot MCP
Server Configuration
Describes the environment variables required to run the server.
| Name | Required | Description | Default |
|---|---|---|---|
| CALENDARS_JSON | No | JSON array of named calendar feeds, e.g. [{"id": "work", "url": "https://..."}]. Takes precedence over CALENDAR_ICS_URL. | |
| CALENDAR_ICS_URL | No | A single HTTPS or webcal:// calendar feed (ICS). | |
| CALENDAR_ALLOWED_HOSTS | No | Optional comma-separated host allowlist, e.g. outlook.office365.com,calendar.google.com. Strongly recommended. | |
| CALENDAR_DEFAULT_TIMEZONE | No | IANA timezone used when a query does not specify one. Default is America/New_York. | America/New_York |
| CALENDAR_CACHE_TTL_SECONDS | No | Feed cache lifetime in seconds. Default is 300. | 300 |
Instructions
Guidance the server publishes about itself, which clients place ahead of the tool catalog so the model reads it before choosing anything.
This server publishes no instructions, or was last inspected before Glama recorded them.
Capabilities
Features and capabilities supported by this server
Protocol revision2025-11-25
| Capability | Details |
|---|---|
| tools | {
"listChanged": true
} |
Tools
Functions exposed to the LLM to take actions
| Name | Description |
|---|---|
| get_availabilityA | Return privacy-safe busy intervals for the configured calendars. Event names, locations, attendees, and notes are never returned. |
| find_free_slotsC | Find privacy-safe free intervals across configured calendars during stated working hours. |
| get_calendar_statusA | Return source-health and cache metadata only; it does not reveal calendar content. |
Prompts
Interactive templates invoked by user choice
| Name | Description |
|---|---|
No prompts | |
Resources
Contextual data attached and managed by the client
| Name | Description |
|---|---|
No resources | |
TDQS
Scored across 3 tools
Each tool serves a clearly distinct purpose: one returns busy intervals, one returns free slots, and one returns only health/cache metadata. There is no overlap in what an agent would select them for.
All three tool names follow a consistent lowercase snake_case verb_noun pattern: get_availability, find_free_slots, get_calendar_status. The pattern is predictable and readable across the set.
Three tools is a well-scoped size for a focused calendar-availability server. Each tool maps to a distinct operation an agent would need, with no redundancy or bloat.
For the stated purpose of privacy-safe availability, the server covers the essential operations: busy intervals, free slots, and source/cache health. There are no obvious dead ends or missing core capabilities within this narrow domain.